Image-forming apparatus

An image-forming apparatus, comprising:

• a plurality of process cartridges each having a toner and an image bearing member and each forming an image with a different color, and
• an intermediate transfer member that, in order to carry out secondary transfer to a transfer material, transports a toner image provided by primary transfer from the image bearing member, wherein
• the toner comprises a toner particle that contains a toner base particle and an organosilicon polymer on the surface of the toner base particle;
• the organosilicon polymer has the structure given by formula (1) below;
• the organosilicon polymer forms protruded portions on the surface of the toner base particle;
• wherein,
• in a flat image provided by observing the toner cross section with a scanning transmission electron microscope STEM, drawing a line along the circumference of the toner base particle surface, and converting based on this line along the circumference, and
• assuming that the length of the line along the circumference for a segment where a protruded portion and the toner base particle form a continuous interface is taken as a protrusion width w, the maximum length of a protruded portion in the direction normal to the protrusion width w is taken as a protrusion diameter D, and the length, in the line segment that forms the protrusion diameter D, from the peak of a protruded portion to the line along the circumference is taken as a protrusion height H,
• the numerical proportion P(D/w), in protruded portions having a protrusion height H from 40 nm to 300 nm, of protruded portions having a ratio D/w of the protrusion diameter D to the protrusion width w from 0.33 to 0.80, is at least 70 number %;
• and wherein
• one of the plurality of process cartridges has a carbon black-containing black toner;
• and
• the weight-average particle diameter of the black toner is smaller than the weight-average particle diameter of the toner present in the other process cartridges
• R—SiO3/2 (1)
• in the formula, R represents an alkyl group having from 1 to 6 carbons or a phenyl group.